git-svn-id: svn://svn.h5l.se/heimdal/trunk/heimdal@11344 ec53bebd-3082-4978-b11e-865c3cabbd6b
		
			
				
	
	
		
			420 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			420 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * Copyright (c) 1997 - 2002 Kungliga Tekniska Högskolan
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 * (Royal Institute of Technology, Stockholm, Sweden). 
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 * All rights reserved. 
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 *
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 * Redistribution and use in source and binary forms, with or without 
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 * modification, are permitted provided that the following conditions 
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 * are met: 
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 *
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 * 1. Redistributions of source code must retain the above copyright 
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 *    notice, this list of conditions and the following disclaimer. 
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 *
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 * 2. Redistributions in binary form must reproduce the above copyright 
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 *    notice, this list of conditions and the following disclaimer in the 
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 *    documentation and/or other materials provided with the distribution. 
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 *
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 * 3. Neither the name of the Institute nor the names of its contributors 
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 *    may be used to endorse or promote products derived from this software 
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 *    without specific prior written permission. 
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 *
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 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND 
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 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
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 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
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 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE 
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 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 
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 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 
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 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 
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 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 
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 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 
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 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 
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 * SUCH DAMAGE. 
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 */
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#include "gssapi_locl.h"
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RCSID("$Id$");
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OM_uint32
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gss_krb5_get_remotekey(const gss_ctx_id_t context_handle,
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		       krb5_keyblock **key)
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{
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    krb5_keyblock *skey;
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    krb5_auth_con_getremotesubkey(gssapi_krb5_context,
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				  context_handle->auth_context, 
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				  &skey);
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    if(skey == NULL)
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	krb5_auth_con_getlocalsubkey(gssapi_krb5_context,
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				     context_handle->auth_context, 
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				     &skey);
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    if(skey == NULL)
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	krb5_auth_con_getkey(gssapi_krb5_context,
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			     context_handle->auth_context, 
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			     &skey);
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    if(skey == NULL)
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	return GSS_S_FAILURE;
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    *key = skey;
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    return 0;
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}
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static OM_uint32
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unwrap_des
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           (OM_uint32 * minor_status,
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            const gss_ctx_id_t context_handle,
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            const gss_buffer_t input_message_buffer,
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            gss_buffer_t output_message_buffer,
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            int * conf_state,
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            gss_qop_t * qop_state,
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	    krb5_keyblock *key
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           )
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{
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  u_char *p, *pad;
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  size_t len;
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  MD5_CTX md5;
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  u_char hash[16], seq_data[8];
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  des_key_schedule schedule;
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  des_cblock deskey;
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  des_cblock zero;
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  int i;
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  int32_t seq_number;
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  size_t padlength;
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  OM_uint32 ret;
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  int cstate;
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  p = input_message_buffer->value;
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  ret = gssapi_krb5_verify_header (&p,
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				   input_message_buffer->length,
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				   "\x02\x01");
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  if (ret) {
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      *minor_status = 0;
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      return ret;
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  }
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  if (memcmp (p, "\x00\x00", 2) != 0)
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    return GSS_S_BAD_SIG;
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  p += 2;
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  if (memcmp (p, "\x00\x00", 2) == 0) {
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      cstate = 1;
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  } else if (memcmp (p, "\xFF\xFF", 2) == 0) {
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      cstate = 0;
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  } else
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      return GSS_S_BAD_MIC;
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  p += 2;
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  if(conf_state != NULL)
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      *conf_state = cstate;
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  if (memcmp (p, "\xff\xff", 2) != 0)
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    return GSS_S_DEFECTIVE_TOKEN;
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  p += 2;
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  p += 16;
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  len = p - (u_char *)input_message_buffer->value;
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  if(cstate) {
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      /* decrypt data */
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      memcpy (&deskey, key->keyvalue.data, sizeof(deskey));
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      for (i = 0; i < sizeof(deskey); ++i)
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	  deskey[i] ^= 0xf0;
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      des_set_key (&deskey, schedule);
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      memset (&zero, 0, sizeof(zero));
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      des_cbc_encrypt ((void *)p,
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		       (void *)p,
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		       input_message_buffer->length - len,
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		       schedule,
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		       &zero,
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		       DES_DECRYPT);
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      memset (deskey, 0, sizeof(deskey));
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      memset (schedule, 0, sizeof(schedule));
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  }
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  /* check pad */
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  pad = (u_char *)input_message_buffer->value + input_message_buffer->length - 1;
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  padlength = *pad;
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  for (i = padlength; i > 0 && *pad == padlength; i--, pad--)
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    ;
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  if (i != 0)
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    return GSS_S_BAD_MIC;
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  MD5_Init (&md5);
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  MD5_Update (&md5, p - 24, 8);
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  MD5_Update (&md5, p, input_message_buffer->length - len);
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  MD5_Final (hash, &md5);
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  memset (&zero, 0, sizeof(zero));
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  memcpy (&deskey, key->keyvalue.data, sizeof(deskey));
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  des_set_key (&deskey, schedule);
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  des_cbc_cksum ((void *)hash, (void *)hash, sizeof(hash),
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		 schedule, &zero);
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  if (memcmp (p - 8, hash, 8) != 0)
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    return GSS_S_BAD_MIC;
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  /* verify sequence number */
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  krb5_auth_getremoteseqnumber (gssapi_krb5_context,
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				context_handle->auth_context,
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				&seq_number);
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  seq_data[0] = (seq_number >> 0)  & 0xFF;
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  seq_data[1] = (seq_number >> 8)  & 0xFF;
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  seq_data[2] = (seq_number >> 16) & 0xFF;
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  seq_data[3] = (seq_number >> 24) & 0xFF;
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  memset (seq_data + 4,
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	  (context_handle->more_flags & LOCAL) ? 0xFF : 0,
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	  4);
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  p -= 16;
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  des_set_key (&deskey, schedule);
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  des_cbc_encrypt ((void *)p, (void *)p, 8,
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		   schedule, (des_cblock *)hash, DES_DECRYPT);
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  memset (deskey, 0, sizeof(deskey));
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  memset (schedule, 0, sizeof(schedule));
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  if (memcmp (p, seq_data, 8) != 0) {
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    return GSS_S_BAD_MIC;
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  }
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  krb5_auth_con_setremoteseqnumber (gssapi_krb5_context,
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				context_handle->auth_context,
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				++seq_number);
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  /* copy out data */
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  output_message_buffer->length = input_message_buffer->length
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    - len - padlength - 8;
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  output_message_buffer->value  = malloc(output_message_buffer->length);
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  if(output_message_buffer->length != 0 && output_message_buffer->value == NULL)
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      return GSS_S_FAILURE;
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  memcpy (output_message_buffer->value,
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	  p + 24,
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	  output_message_buffer->length);
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  return GSS_S_COMPLETE;
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}
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static OM_uint32
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unwrap_des3
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           (OM_uint32 * minor_status,
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            const gss_ctx_id_t context_handle,
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            const gss_buffer_t input_message_buffer,
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            gss_buffer_t output_message_buffer,
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            int * conf_state,
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            gss_qop_t * qop_state,
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	    krb5_keyblock *key
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           )
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{
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  u_char *p, *pad;
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  size_t len;
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  u_char seq[8];
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  krb5_data seq_data;
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  u_char cksum[20];
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  int i;
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  int32_t seq_number;
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  size_t padlength;
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  OM_uint32 ret;
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  int cstate;
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  krb5_crypto crypto;
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  Checksum csum;
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  int cmp;
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  p = input_message_buffer->value;
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  ret = gssapi_krb5_verify_header (&p,
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				   input_message_buffer->length,
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				   "\x02\x01");
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  if (ret) {
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      *minor_status = 0;
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      return ret;
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  }
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  if (memcmp (p, "\x04\x00", 2) != 0) /* HMAC SHA1 DES3_KD */
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    return GSS_S_BAD_SIG;
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  p += 2;
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  if (memcmp (p, "\x02\x00", 2) == 0) {
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    cstate = 1;
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  } else if (memcmp (p, "\xff\xff", 2) == 0) {
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    cstate = 0;
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  } else
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    return GSS_S_BAD_MIC;
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  p += 2;
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  if(conf_state != NULL)
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    *conf_state = cstate;
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  if (memcmp (p, "\xff\xff", 2) != 0)
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    return GSS_S_DEFECTIVE_TOKEN;
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  p += 2;
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  p += 28;
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  len = p - (u_char *)input_message_buffer->value;
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  if(cstate) {
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      /* decrypt data */
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      krb5_data tmp;
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      ret = krb5_crypto_init(gssapi_krb5_context, key,
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			     ETYPE_DES3_CBC_NONE, &crypto);
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      if (ret) {
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	  gssapi_krb5_set_error_string ();
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	  *minor_status = ret;
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	  return GSS_S_FAILURE;
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      }
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      ret = krb5_decrypt(gssapi_krb5_context, crypto, KRB5_KU_USAGE_SEAL,
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			 p, input_message_buffer->length - len, &tmp);
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      krb5_crypto_destroy(gssapi_krb5_context, crypto);
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      if (ret) {
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	  gssapi_krb5_set_error_string ();
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	  *minor_status = ret;
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	  return GSS_S_FAILURE;
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      }
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      assert (tmp.length == input_message_buffer->length - len);
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      memcpy (p, tmp.data, tmp.length);
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      krb5_data_free(&tmp);
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  }
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  /* check pad */
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  pad = (u_char *)input_message_buffer->value + input_message_buffer->length - 1;
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  padlength = *pad;
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  for (i = padlength; i > 0 && *pad == padlength; i--, pad--)
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    ;
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  if (i != 0)
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    return GSS_S_BAD_MIC;
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  /* verify sequence number */
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  krb5_auth_getremoteseqnumber (gssapi_krb5_context,
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				context_handle->auth_context,
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				&seq_number);
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  seq[0] = (seq_number >> 0)  & 0xFF;
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  seq[1] = (seq_number >> 8)  & 0xFF;
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  seq[2] = (seq_number >> 16) & 0xFF;
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  seq[3] = (seq_number >> 24) & 0xFF;
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  memset (seq + 4,
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	  (context_handle->more_flags & LOCAL) ? 0xFF : 0,
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	  4);
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  p -= 28;
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  ret = krb5_crypto_init(gssapi_krb5_context, key,
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			 ETYPE_DES3_CBC_NONE, &crypto);
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  if (ret) {
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      gssapi_krb5_set_error_string ();
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      *minor_status = ret;
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      return GSS_S_FAILURE;
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  }
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  {
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      des_cblock ivec;
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      memcpy(&ivec, p + 8, 8);
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      ret = krb5_decrypt_ivec (gssapi_krb5_context,
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			       crypto,
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			       KRB5_KU_USAGE_SEQ,
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			       p, 8, &seq_data,
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			       &ivec);
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  }
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  krb5_crypto_destroy (gssapi_krb5_context, crypto);
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  if (ret) {
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      gssapi_krb5_set_error_string ();
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      *minor_status = ret;
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      return GSS_S_FAILURE;
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  }
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  if (seq_data.length != 8) {
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      krb5_data_free (&seq_data);
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      return GSS_S_BAD_MIC;
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  }
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  cmp = memcmp (seq, seq_data.data, seq_data.length);
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  krb5_data_free (&seq_data);
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  if (cmp != 0) {
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      return GSS_S_BAD_MIC;
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  }
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  krb5_auth_con_setremoteseqnumber (gssapi_krb5_context,
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				context_handle->auth_context,
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				++seq_number);
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  /* verify checksum */
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  memcpy (cksum, p + 8, 20);
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  memcpy (p + 20, p - 8, 8);
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  csum.cksumtype = CKSUMTYPE_HMAC_SHA1_DES3;
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  csum.checksum.length = 20;
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  csum.checksum.data   = cksum;
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  ret = krb5_crypto_init(gssapi_krb5_context, key, 0, &crypto);
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  if (ret) {
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      gssapi_krb5_set_error_string ();
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      *minor_status = ret;
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      return GSS_S_FAILURE;
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  }
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  ret = krb5_verify_checksum (gssapi_krb5_context, crypto,
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			      KRB5_KU_USAGE_SIGN,
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			      p + 20,
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			      input_message_buffer->length - len + 8,
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			      &csum);
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  krb5_crypto_destroy (gssapi_krb5_context, crypto);
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  if (ret) {
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      gssapi_krb5_set_error_string ();
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      *minor_status = ret;
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      return GSS_S_FAILURE;
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  }
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  /* copy out data */
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  output_message_buffer->length = input_message_buffer->length
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    - len - padlength - 8;
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  output_message_buffer->value  = malloc(output_message_buffer->length);
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						|
  if(output_message_buffer->length != 0 && output_message_buffer->value == NULL)
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      return GSS_S_FAILURE;
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  memcpy (output_message_buffer->value,
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	  p + 36,
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	  output_message_buffer->length);
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  return GSS_S_COMPLETE;
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}
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OM_uint32 gss_unwrap
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           (OM_uint32 * minor_status,
 | 
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            const gss_ctx_id_t context_handle,
 | 
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            const gss_buffer_t input_message_buffer,
 | 
						|
            gss_buffer_t output_message_buffer,
 | 
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            int * conf_state,
 | 
						|
            gss_qop_t * qop_state
 | 
						|
           )
 | 
						|
{
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						|
  krb5_keyblock *key;
 | 
						|
  OM_uint32 ret;
 | 
						|
  krb5_keytype keytype;
 | 
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 | 
						|
  if (qop_state != NULL)
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      *qop_state = GSS_C_QOP_DEFAULT;
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  ret = gss_krb5_get_remotekey(context_handle, &key);
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						|
  if (ret) {
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      gssapi_krb5_set_error_string ();
 | 
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      *minor_status = ret;
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      return GSS_S_FAILURE;
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  }
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  krb5_enctype_to_keytype (gssapi_krb5_context, key->keytype, &keytype);
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  switch (keytype) {
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  case KEYTYPE_DES :
 | 
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      ret = unwrap_des (minor_status, context_handle,
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			input_message_buffer, output_message_buffer,
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			conf_state, qop_state, key);
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      break;
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  case KEYTYPE_DES3 :
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      ret = unwrap_des3 (minor_status, context_handle,
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			 input_message_buffer, output_message_buffer,
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			 conf_state, qop_state, key);
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      break;
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  default :
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      *minor_status = KRB5_PROG_ETYPE_NOSUPP;
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      ret = GSS_S_FAILURE;
 | 
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      break;
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  }
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  krb5_free_keyblock (gssapi_krb5_context, key);
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  return ret;
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}
 |